5 Reasons a Crash Is Unlikely

Monday's Boston bombing sent stock prices tumbling and has given investors a new reason to reconsider risk. The Standard & Poor's 500 index (ticker: SPY), a benchmark for U.S. stocks, is up 10% so far this year--as much as it has historically returned in a full year. It trades just above levels reached in the spring of 2000 and autumn of 2007, both...